replace pyrsistent.PMap, immutables.Map, immutabledict with constantdict #3373

Job	Run time
Mypy	1m 24s
Typos	3s
Documentation	1m 37s
Conda Examples	1m 56s
Tests for downstream project arraycontext	2m 44s
Pylint	1m 19s
Tests for downstream project meshmode	9m 53s
Tests for downstream project grudge	10m 31s
Conda Pytest (ubuntu-latest)	4m 10s
Conda Pytest with Intel CL	4m 6s
Tests for downstream project pytential	45m 13s
Conda Pytest (macos-latest)	4m 12s
Tests for downstream project pytato	6m 28s
Conda Pytest without arg check	3m 51s
Conda Pytest Twice (for cache behavior)	5m 21s
Ruff	7s
Tests for downstream project Firedrake	2m 51s
Validate CITATION.cff	7s
	1h 45m 53s

Provide feedback